C-h i opens an info-mode buffer with a list of available manuals, and if you scroll down to Elisp and press enter you can read the Emacs Lisp Reference Manual, or to Org Mode and press enter you can read the Org Mode Manual.

To determine what key shortcuts are available in a buffer, say because you’re in an info-mode buffer deep in the Org Mode Manual and you’re trying to get back up to the list of manuals, press C-h m to open another buffer in describe-mode, which will explain that from info-mode a ^ goes up a from a node to its parent node, and, when you’re finished, q quits and restores the info-mode buffer to whatever was in it before you started reading the manuals.

C-h m results are customized to the type of buffer and the modes active within it: from the org-mode buffer I’m typing this in, for instance, they include: